This invention relates generally to optical readers. In one aspect, it relates to an optical reader using ultraviolet wavelengths for scanning printed indicia.
With the growing numbers of computer users connecting to the xe2x80x9cInternet,xe2x80x9d many companies are seeking the substantial commercial opportunities presented by such a large user base. For example, one technology which exists allows a television (xe2x80x9cTVxe2x80x9d) signal to trigger a computer response in which the consumer will be guided to a personalized web page. The source of the triggering signal may be a TV, video tape recorder, or radio. For example, if a viewer is watching a TV program in which an advertiser offers viewer voting, the advertiser may transmit a unique signal within the television signal which controls a program known as a xe2x80x9cbrowserxe2x80x9d on the viewer""s computer to automatically display the advertiser""s web page. The viewer then simply makes a selection which is then transmitted back to the advertiser.
In order to provide the viewer with the capability of responding to a wide variety of companies using this technology, a database of company information and Uniform Resource Locator (xe2x80x9cURLxe2x80x9d) codes is necessarily maintained in the viewer""s computer, requiring continuous updates. URLs are short strings of data that identify resources on the Internet: documents, images, downloadable files, services, electronic mailboxes, and other resources. URLs make resources available under a variety of naming schemes and access methods such as HTTP, FTP, and Internet mail, addressable in the same simple way. URLs reduce the tedium of xe2x80x9clogin to this server, then issue this magic command . . . xe2x80x9d down to a single click. The Internet uses URLs to specify the location of files on other servers. A URL includes the type of resource being accessed (e.g., Web, gopher, FTP), the address of the server, and the location of the file. The URL can point to any file on any networked computer. Current technology requires the viewer to perform periodic updates to obtain the most current URL database. This aspect of the current technology is cumbersome since the update process requires downloading information to the viewer""s computer. Moreover, the likelihood for error in performing the update, and the necessity of redoing the update in the event of a later computer crash, further complicates the process. Additionally, current technologies are limited in the number of companies which may be stored in the database. This is a significant limitation since world-wide access presented by the Internet and the increasing number of companies connecting to perform on-line E-commerce necessitates a large database.
Many types of optical readers are known, however, their cost and complexity have heretofore limited their use primarily to industrial and commercial users. Now, many new network-based technologies are being developed for home users which involve optical scanning. Thus, the need for a simple, low cost optical reader which can be attached to a personal computer has emerged.
The present invention disclosed and claimed herein comprises, in one aspect thereof, an optical reader for reading a bar code having ultraviolet-wavelength-responsive properties. The optical reader includes an ultraviolet light source, a photodetector, an optical system and a decoder. The ultraviolet light source generates ultraviolet light having a wavelength shorter than visible light and longer than X-rays for illuminating a target region. The photodetector generates output electrical signals indicative of light incident thereon having a wavelength within a predetermined range of wavelengths. The optical system includes a projection portion and a collection portion. The projection portion directs the ultraviolet light along a projection path extending from the ultraviolet light source to the target region. The collection portion collects the light from a bar code when the bar code occupies the target region and directs the collected light along a collection path extending from the target region to the photodetector. The decoder receives the output electrical signals of the photodetector and produces, in response thereto, electrical signals indicative of information encoded in the bar code.